-
Yuzo Suzuki,
Takafumi Suda,
Kazuhiro Asada,
Seiichi Miwa,
Masako Suzuki, Michio Fujie,
Kazuki Furuhashi,
Yutaro Nakamura,
Naoki Inui,
Toshihiro Shirai,
Hiroshi Hayakawa,
Hirotoshi Nakamura,
Kingo Chida
[show abstract]
[hide abstract]
ABSTRACT: Tuberculosis (TB) continues to be a major health problem, and there are few biomarkers for predicting prognosis. Indoleamine 2,3-dioxygenase (IDO), a potent immunoregulatory molecule, catalyzes the rate-limiting step of tryptophan (Trp) degradation in the kynurenine (Kyn) pathway. An increase in IDO activity determined by the serum Trp/Kyn ratio has been shown to be associated with poor prognosis in cancers and bacteremia. In TB, however, there are no studies measuring serum IDO activity to determine its clinical significance. We evaluated serum IDO activity with 174 pulmonary TB (PTB) patients and 85 controls, using liquid chromatography/electrospray ionization tandem mass spectrometry. IDO activity was estimated by calculating the serum Kyn-to-Trp ratio. PTB patients had significantly higher Kyn concentrations and IDO activity and significantly lower Trp concentrations (P < 0.0001, P < 0.0001, and P < 0.0001, respectively) than the controls. Of 174 PTB patients, 39 (22.4%) died. The patients who died had significantly higher concentrations of Kyn and significantly lower Trp concentrations, resulting in significantly higher IDO activity (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). In a receiver operating characteristic (ROC) analysis, serum IDO activity had the highest area under the curve (0.850), and this activity was an independent prognostic factor in multivariate analysis. These results suggest that serum IDO activity can be used as a novel prognostic marker in PTB.
Clinical and vaccine immunology: CVI 01/2012; 19(3):436-42. · 2.37 Impact Factor
-
Satoki Nakamura,
Tomonari Takemura,
Lin Tan,
Yasuyuki Nagata,
Daisuke Yokota,
Isao Hirano,
Kazuyuki Shigeno,
Kiyoshi Shibata, Michio Fujie,
Shinya Fujisawa,
Kazunori Ohnishi
[show abstract]
[hide abstract]
ABSTRACT: Chronic myelogenous leukemia (CML) is characterized by a reciprocal chromosomal translocation (9;22) that generates the Bcr-Abl fusion gene. BCR-ABL transforming activity is mediated by critical downstream signaling pathways that are aberrantly activated by tyrosine kinases. However, the mechanisms of BCR-ABL anti-apoptotic effects and the signaling pathways by which BCR-ABL influences apoptosis in BCR-ABL-expressing cells are poorly defined. In this study, we found that treatment with ABL kinase inhibitors or depletion of BCR-ABL induced the expression of RAB45 messenger RNA and protein and induced apoptosis via reduction of mitochondrial membrane potential and p38 activation in CML cell lines and BCR-ABL(+) progenitor cells from CML patients. Overexpressed RAB45 induced the activation of caspases-3 and -9 and reduced the expression of Survivin, XIAP, c-IAP1 and c-IAP2 in CML cells. Moreover, in colony-forming cells derived from CML-aldehyde dehydrogenase(hi)/CD34(+) cells, treatment with ABL kinase inhibitors induced RAB45 expression and reduced mitochondrial membrane potential, resulting in inhibited colony formation of Bcr-Abl(+) progenitor cells. The overexpression of RAB45 significantly decreased colony numbers and induced apoptosis through the activation of caspases-3 and -9. Furthermore, the overexpression of RAB45 increased the phosphorylation levels of p38, resulting in the induction of apoptosis and inhibition of proliferation of CML progenitor cells. Our results identify a new signaling molecule involved in BCR-ABL modulation of apoptosis and suggest that RAB45 induction strategies may have therapeutic utility in patients with CML.
Carcinogenesis 09/2011; 32(12):1758-72. · 5.70 Impact Factor
-
Yuzo Suzuki,
Takafumi Suda,
Koushi Yokomura,
Masako Suzuki, Michio Fujie,
Kazuki Furuhashi,
Dai Hahimoto,
Noriyuki Enomto,
Tomoyuki Fujisawa,
Yutaro Nakamura,
Naoki Inui,
Yutaka Nakano,
Hirotoshi Nakamura,
Kingo Chida
[show abstract]
[hide abstract]
ABSTRACT: Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step of tryptophan (Trp) degradation in the kynurenine (Kyn) pathway. By depleting Trp, IDO plays a critical role in inducing immune suppression and tolerance. The aim of present study was to investigate serum IDO activity, determined by Kyn-to-Trp ratio (Kyn/Trp ratio), in community-acquired pneumonia (CAP) and to examine its clinical significance. METODS: This study subjects consisted of 129 consecutive patients with CAP and 64 healthy controls. The concentrations of Kyn and Trp were measured simultaneously by liquid chromatography/electrospray ionization tandem mass spectrometry.
The CAP patients had significantly higher Kyn concentrations and significant lower Trp concentrations than the controls (p < 0.0001 and p < 0.0001, respectively). Accordingly, IDO activity was significantly higher (2.4-fold) in the patients than in the controls (p < 0.0001). IDO activity correlated well with PSI (Pneumonia Severity Index) and CURB65 (p = 0.0005 and p < 0.0001, respectively). Moreover, the IDO activity and Kyn concentration were significantly higher in the nonsurvivors and were found to predict mortality in multivariate analysis.
IDO activity was increased in CAP, and this activity was associated with the severity and outcome of this disease. These results suggest that IDO activity can predict prognosis of CAP.
The Journal of infection 07/2011; 63(3):215-22. · 4.13 Impact Factor
-
Kenji Tsunekawa,
Mitsuji Yamashita, Michio Fujie,
Taishi Niimi,
Takuya Suyama,
Kazuhide Asai,
Satoru Ito,
Junko Yamashita,
Manabu Yamada,
Nobuhisa Ozaki,
Satoki Nakamura
Phosphorus Sulfur and Silicon and the Related Elements 04/2011; Sulfur(and Silicon and the Related Elements):936-944. · 0.72 Impact Factor
-
Satoki Nakamura,
Yasuyuki Nagata,
Lin Tan,
Tomonari Takemura,
Kiyoshi Shibata, Michio Fujie,
Shinya Fujisawa,
Yasutaka Tanaka,
Mitsuo Toda,
Reiko Makita,
Kenji Tsunekawa,
Manabu Yamada,
Mayumi Yamaoka,
Junko Yamashita,
Kazunori Ohnishi,
Mitsuji Yamashita
[show abstract]
[hide abstract]
ABSTRACT: The immediately-early response gene 5 (IER5) has been reported to be induced by γ-ray irradiation and to play a role in the induction of cell death caused by radiation. We previously identified IER5 as one of the 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP)-induced transcriptional responses in AML cells, using microarrays that encompassed the entire human genome. However, the biochemical pathway and mechanisms of IER5 function in regulation of the cell cycle remain unclear. In this study, we investigated the involvement of IER5 in the cell cycle and in cell proliferation of acute myeloid leukemia (AML) cells. We found that the over-expression of IER5 in AML cell lines and in AML-derived ALDH(hi) (High Aldehyde Dehydrogenase activity)/CD34(+) cells inhibited their proliferation compared to control cells, through induction of G2/M cell cycle arrest and a decrease in Cdc25B expression. Moreover, the over-expression of IER5 reduced colony formation of AML-derived ALDH(hi)/CD34(+) cells due to a decrease in Cdc25B expression. In addition, over-expression of Cdc25B restored TMPP inhibitory effects on colony formation in IER5-suppressed AML-derived ALDH(hi)/CD34(+) cells. Furthermore, the IER5 reduced Cdc25B mRNA expression through direct binding to Cdc25B promoter and mediated its transcriptional attenuation through NF-YB and p300 transcriptinal factors. In summary, we found that transcriptional repression mediated by IER5 regulates Cdc25B expression levels via the release of NF-YB and p300 in AML-derived ALDH(hi)/CD34(+) cells, resulting in inhibition of AML progenitor cell proliferation through modulation of cell cycle. Thus, the induction of IER5 expression represents an attractive target for AML therapy.
PLoS ONE 01/2011; 6(11):e28011. · 4.09 Impact Factor
-
Manabu Yamada,
Mitsuji Yamashita,
Takuya Suyama,
Junko Yamashita,
Kazuhide Asai,
Taishi Niimi,
Nobuhisa Ozaki, Michio Fujie,
Kasthuraiah Maddali,
Satoki Nakamura,
Kazunori Ohnishi
[show abstract]
[hide abstract]
ABSTRACT: 4-Bromo-3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (3c) was first synthesized from 3,4-dimethyl-1-phenyl-2-phospholene 1-oxide (2c) by a bromo-radical substitution reaction occurred at C-4 position by N-bromosuccinimide and 2,2'-azobisisobutyronitrile. The novel phospha sugar analogue 3c exerted high anti-proliferative effect on U937 cells evaluated by MTT in vitro methods and was much more efficient than that of Gleevec, which is known as a molecule targeting chemotherapeutical agent. The substitution of 2-phospholenes at C-3 and C-4 position with methyl groups as well as 4-bromo substituent suggests a good anti-proliferative effect.
Bioorganic & medicinal chemistry letters 10/2010; 20(19):5943-6. · 2.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Essential amino acid tryptophan (Trp) is mainly catabolized by indoleamine 2,3-dioxygenase, which leads to the formation of kynurenine (Kyn). In this study, we reexamined whether an increased indoleamine 2,3-dioxygenase activity, as estimated by the Kyn/Trp ratio (μM/mM), is associated with atherosclerotic parameters in hemodialysis (HD) patients. Serum Trp and Kyn were measured in 243 HD patients by liquid chromatography/electrospray ionization tandem mass spectrometry. We measured carotid artery intima-medial thickness, brachial-ankle pulse wave velocity, ankle-brachial pressure index, and the cardio-ankle vascular index. Log-transformed Kyn/Trp ratio was significantly correlated with log-transformed time on HD (ρ=0.28, P<0.01), log-transformed highly sensitive C-reactive protein (ρ=0.20, P<0.01), and peripheral total lymphocyte count (ρ=-0.13, P<0.05). A significant association was found between log-transformed Kyn/Trp ratio and mean carotid artery intima-medial thickness (ρ=0.18, P<0.01). Mean carotid artery intima-medial thickness was significantly higher in the lowest quartile of Kyn/Trp ratio (<165) (0.62±0.12 mm) when compared with the highest quartile (≥304) (0.68±0.15 mm) (P<0.01). Ankle-brachial pressure index was lower in the second quartile (1.01±0.20), the third quartile (1.01±0.19), and the fourth quartile (1.03±0.15) compared with that in the first quartile (1.09±0.13) (P<0.05). It follows from these findings that the Kyn/Trp ratio increases with time on HD, and is associated with advanced atherosclerotic changes in chronic HD patients.
Hemodialysis International 10/2010; 14(4):418-24. · 1.54 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A new type of dendritic molecules Gd-DTPA-XDA-D1-Glc(OH), which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with two glucose moieties on the molecular surfaces, were readily synthesized with high yield. The structures were established by IR, (1)H, (13)C NMR, and mass spectral studies. Its bio-distribution patterns were evaluated on rats.
Bioorganic & medicinal chemistry letters 02/2010; 20(3):932-4. · 2.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A novel phospha sugar analogue, 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DBMPP), was prepared from 1-phenyl-3-methyl-2- phospholene 1-oxide and evaluated by in vitro MTT method forleukemia cells and microscopic observations forsolid tumor cells, e.g., stomach cancer cells. The evaluation revealed clearly that the synthesized phospha sugar analogue DBMPP has competent potentials and excellent anti-cancer activities that killed selectively and specifically the leukemia cells of cell lines of K562 and U937 but did not give any damages on healthy leukocyte. Moreover it was revealed that DBMPP killed solid cancer cells such as stomach cancer cells and melanoma of cell lines of MKN45 and G361. Therefore, DBMPP should exert anti-proliferative effects for different kinds of tumor cells based on the in vitro evaluations. The cell cycle analyses by flow cytometry for K562 and U937 cells clearly demonstrated that the mechanism of the anti-proliferative effect on the human tumor cells is apoptosis induced by DBMPP.
Journal of Environmental Biology 11/2009; 30(6):945-50. · 0.64 Impact Factor
-
Satoki Nakamura,
Mitsuji Yamashita,
Daisuke Yokota,
Isao Hirano,
Takaaki Ono, Michio Fujie,
Kiyoshi Shibata,
Taishi Niimi,
Takuya Suyama,
Kasthuraiah Maddali,
Kazuhide Asai,
Junko Yamashita,
Yukiko Iguchi,
Kazunori Ohnishi
[show abstract]
[hide abstract]
ABSTRACT: Here, we synthesized two phospha sugar derivatives, 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP) and 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide (DMPP) by reacting 3-methyl-1-phenyl-2-phospholene 1-oxide with bromine, and investigated their potential as antileukemic agents in cell lines. Both agents showed inhibitory effects on leukemia cell proliferation, with mean IC(50) values of 6.25 micromol/L for TMPP and 23.7 micromol/L for DMPP, indicating that inhibition appeared to be dependent on the number of bromine atoms in the structure. Further, TMPP at 10 micromol/L and DMPP at 20 micromol/L induced G2/M cell cycle block in leukemia cells, and TMPP at 20 micromol/L induced apoptosis in these cells. TMPP treatment effected a reduction in both cell cycle progression signals (FoxM1, KIS, Cdc25B, Cyclin D1, Cyclin A, and Aurora-B) and tumor cell survival (p27(Kip1) and p21(Cip1)), as well as induced the activation of caspase-3 and -9. Further, treatment with TMPP significantly reduced the viability of AML specimens derived from AML patients, but only slightly reduced the viability of normal ALDH(hi) progenitor cells. We also observed that FoxM1 mRNA was overexpressed in AML cells, and treatment with TMPP reduced FoxM1 mRNA expression in AML cells. Here, we report on the synthesis of TMPP and DMPP and demonstrate that these agents hinder proliferation of leukemia cells by FoxM1 suppression, which leads to G2/M cell cycle block and subsequent caspase-3-dependent apoptosis in acute leukemia cells. These agents may facilitate the development of new strategies in targeted antileukemic therapy.
Investigational New Drugs 06/2009; 28(4):381-91. · 3.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Indoleamine 2,3-dioxygenase (IDO) catalyzes the rate-limiting step of tryptophan (Trp) degradation along the kynurenine (Kyn) pathway. By depleting tryptophan, IDO is considered to be a fundamental immune escape mechanism for tumor cells. However, IDO expression in lung cancer has not been explored thoroughly. Thus, the present study investigated IDO activity determined by serum Trp and Kyn concentrations in lung cancer and the correlation between the IDO activity and clinical parameters.
The concentrations of Trp and Kyn were measured simultaneously by liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) in the sera of 123 patients with lung cancer and 45 healthy controls. The IDO activity was estimated by calculating the serum Kyn-to-Trp ratio (Kyn/Trp ratio).
Trp concentrations were significantly lower in patients with lung cancer than in healthy controls (62.6+/-15.8microM vs. 71.1+/-11.8microM, respectively; p=0.0007), while Kyn concentrations were significantly higher in patients compared with the controls (2.82+/-1.17microM vs. 2.30+/-0.56microM, respectively; p=0.0036). The IDO activity determined by the Kyn/Trp ratio was significantly higher in the patients than in the controls (47.1+/-21.3 vs. 32.9+/-9.10, respectively; p<0.0001). In addition, patients in the advanced stages of lung cancer had significantly lower Trp concentrations and higher IDO activity than those in the early stages (p=0.0058 and p=0.0209, respectively).
IDO activity was increased in lung cancer patients, and higher IDO activity was associated with more advanced stages. These results suggest that increased IDO activity is involved in disease progression of lung cancer, possibly through its immunosuppressive effect.
Lung cancer (Amsterdam, Netherlands) 05/2009; 67(3):361-5. · 3.14 Impact Factor
-
Takayasu Suzuki,
Teruhisa Kazui,
Seiji Yamamoto,
Naoki Washiyama,
Kazuhiro Ohkura,
Kentaro Ohishi,
Abul Hasan Muhammad Bashar,
Katsushi Yamashita,
Hitoshi Terada,
Kazuchika Suzuki,
Satoshi Akuzawa, Michio Fujie
[show abstract]
[hide abstract]
ABSTRACT: Reactive free radical species are thought to be involved in postoperative neurologic dysfunction after antegrade selective cerebral perfusion in brains with old infarction. We assessed the brain protective effect of prophylactically administered edaravone, a free radical scavenger, for antegrade selective cerebral perfusion in brains with or without old infarction in a canine model.
A canine model of old cerebral infarction was created by injecting cylindric silicone embolus into the middle cerebral artery. Animals showing obvious neurologic deficits and surviving 4 weeks or longer were included in the model. Deep hypothermia with antegrade selective cerebral perfusion was performed in both intact (non-edaravone, group A; edaravone-treated, group B) and infarcted animals (non-edaravone, group C; edaravone-treated, group D). Serum concentrations of malondialdehyde, hexanoyl-lysine, glutamate, and venous-arterial lactate difference were measured, and central conduction time and amplitude of somatosensory evoked potentials were assessed during the operation.
Compared with the intact groups, serum concentrations of malondialdehyde and hexanoyl-lysine in group C significantly increased at the end of antegrade selective cerebral perfusion, whereas that of glutamate did so in the rewarming phase. Increases in all these biochemical parameters were suppressed in group D. In group C, the venous-arterial lactate difference was significantly greater in the rewarming phase at 28 degrees C compared with intact groups. A significant prolongation of postoperative central conduction time and decrease in neuronal activity were detected in group C, both of which recovered in group D.
Prophylactic administration of edaravone exerted a significant protective effect against postoperative neurologic dysfunction after antegrade selective cerebral perfusion in a canine model with old cerebral infarction.
The Journal of thoracic and cardiovascular surgery 04/2007; 133(3):710-6. · 3.41 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A purified human urinary trypsin inhibitor (UTI) and its related synthetic peptides were examined to determine whether they could inhibit production of experimental and spontaneous lung metastases by murine Lewis lung carcinoma (3LL) cells. Three peptides, peptide 1, peptide 2 and peptide 3, representing the amino acid sequences within the UTI molecule, were synthesized. UTI and peptide 2 inhibited human leukocyte elastase (HLE). UTI and peptide 3 specifically inhibited human and murine plasmin activity. Peptide 1 had essentially no inhibitory activity. In an in vivo spontaneous metastasis model, multiple s.c. injections of UTI or peptide 3 for 7 days immediately after s.c. tumor cell inoculation significantly inhibited the formation of lung metastasis in CS7BL/6 mice in a dose-dependent manner. UTI reduced lung tumor colonization more effectively than peptide 3. Peptides 1 and 2, however, did not affect the formation of lung metastasis. Inhibition of lung metastasis was not due to direct anti-tumor effects of UTI and peptide 3. In an in vivo experimental metastasis assay, multiple s.c. injections of UTI for 7 days after i.v. tumor cell inoculation inhibited metastatic lung tumor colonization, while peptide 3 did not affect metastasis. Peptides 1 and 2 did not affect the formation of lung metastasis. When examined with an in vitro assay system using a modified Boyden chamber, UTI and peptide 3 suppressed the invasion of tumor cells through Matrigel. UTI and peptide 3 inhibited neither cell proliferation nor the binding of tumor cells to Matrigel and showed no significant suppression of chemotactic migration of tumor cells to fibronectin. Our results suggest that UTI efficiently regulates the mechanism involved in not only the entry into vascular circulation of tumor cells (intravasation, though, at least in part, inhibition of the proteolytic enzyme plasmin) but also the extravasation step of the metastatic process.
International Journal of Cancer 07/2006; 63(3):455 - 462. · 5.44 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We sought to examine the influence on the brain, with or without old infarction, of pH management during antegrade selective cerebral perfusion in a canine model.
A cerebral infarct canine model was created by injecting a cylindrical silicone embolus. Dogs that had obvious neurologic deficits and had survived for 4 weeks or more were included in the model. Deep hypothermia with antegrade selective cerebral perfusion was performed in intact mongrel dogs (alpha-stat: group A, n = 6; pH-stat: group B, n = 6) and mongrel dogs with infarctions (alpha-stat: group C, n = 6; pH-stat: group D, n = 6). Maxillary vein saturation of oxygen, venous-arterial lactate difference, and serum concentrations of malondialdehyde and glutamate were measured and central conduction times and amplitude in somatosensory evoked potentials were assessed during the operation.
During the experimental procedure, the maxillary vein saturation of oxygen was significantly less (P <.05), whereas the venous-arterial lactate difference was significantly greater (P <.05) in the cooling phase to 28 degrees C in group C than in the other groups. The pH-stat group showed significantly greater arterial Paco(2) and lower pH than the alpha-stat group during the period between the cooling to 28 degrees C and the rewarming to 28 degrees C (P <.05). Other intraoperative parameters did not show any difference among the groups. In group C the serum concentrations of malondialdehyde and glutamate significantly increased, as did the central conduction time, whereas in both groups C and D the amplitude ratio decreased significantly.
This experiment suggests that pH-stat management during antegrade selective cerebral perfusion provides more effective protection for a brain with old infarction than alpha-stat management.
Journal of Thoracic and Cardiovascular Surgery 09/2004; 128(3):378-85. · 3.41 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Serine:pyruvate/alanine:glyoxylate aminotransferase (SPT/AGT) is largely located in mitochondria in carnivores, whereas it is entirely found within peroxisomes in herbivores and humans. In rat liver, SPT/AGT is found in both of these organelles, and only the mitochondrial enzyme is markedly induced by glucagon. Although SPT/AGT is a bifunctional enzyme involved in the metabolism of both L-serine and glyoxylate, its contribution to L-serine metabolism is independent of mitochondrial or peroxisomal localization (Xue HH et al., J Biol Chem 274: 16028-16033, 1999). Therefore, the species-specific and food habit-dependent organelle distribution might be required for proper metabolism of glyoxylate at the subcellular site of its formation. Glyoxylate formation from glycolate and that from L-hydroxyproline have been shown to occur in peroxisomes and mitochondria, respectively. The present study found that urinary excretion of oxalate was markedly increased when a large dose of L-hydroxyproline or glycolate was administered to rats. Oxalate formation from L-hydroxyproline but not that from glycolate was significantly reduced when mitochondrial SPT/AGT had been induced by glucagon. The hydroxyproline content of collagen is 10 to 13%, and collagen accounts for about 30% of total animal protein; therefore, these results suggest that an important role of mitochondrial SPT/AGT in carnivores is to convert L-hydroxyproline-derived glyoxylate into glycine in situ, preventing undesirable overflow into the production of oxalate.
Journal of the American Society of Nephrology 05/2003; 14(4):939-46. · 9.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We previously found that bikunin (bik), a Kunitz-type protease inhibitor, suppresses phorbol ester (PMA)-stimulated expression of urokinase-type plasminogen activator (uPA). In the present study, we tried to answer this mechanism using human chondrosarcoma HCS-2/8 cells. Our results showed the following novel findings: (a) the standard form of CD44 (CD44s; 85 kDa) is expressed in both unstimulated and PMA-stimulated cells, while CD44v isoforms containing epitope v9 (110 kDa) are strongly up-regulated in response to treatment with PMA; (b) CD44v isoforms containing epitope v9 present on the same cell exclusively form aggregates in stimulated cells; (c) induction of uPA mRNA expression could be achieved by using a second cross-linker antibody to cross-link Fab monomers of anti-CD44; (d) co-treatment of stimulated cells with anti-CD44 mAb alone or anti-CD44v9 mAb alone suppresses PMA-induced clustering of CD44, which results in inhibition of uPA overexpression; (e) bikunin efficiently disrupts PMA-induced clustering of CD44, but does not prevent PMA-induced up-regulation of CD44v isoforms containing epitope v9; and (f) after exposure to bik, approximately 150-kDa band is mainly detected with immunoprecipitation and this band is shown to be a heterodimer composed of the 110-kDa v9-containing CD44v isoforms and a 45-kDa bik receptor (bik-R). In conclusion, we provide, for the first time, evidence that the bik-R can physically interact with the CD44v isoforms containing epitope v9 and function as a repressor to down-regulate PMA-stimulated uPA expression, at least in part, by preventing clustering of CD44v isoforms containing epitope v9.
Journal of Biological Chemistry 04/2002; 277(10):8022-32. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: l-Serine metabolism in rabbit, dog, and human livers was investigated, focusing on the relative contributions of the three
pathways, one initiated by serine dehydratase, another by serine:pyruvate/alanine:glyoxylate aminotransferase (SPT/AGT), and
the other involving serine hydroxymethyltransferase and the mitochondrial glycine cleavage enzyme system (GCS). Under quasi-physiological
in vitro conditions (1 mm l-serine and 0.25 mmpyruvate), flux through serine dehydratase accounted for only traces, and that through SPT/AGT substantially contributed no
matter whether the enzyme was located in peroxisomes (rabbit and human) or largely in mitochondria (dog). As for flux through
serine hydroxymethyltransferase and GCS, the conversion of serine to glycine occurred fairly rapidly, followed by GCS-mediated
slow decarboxylation of the accumulated glycine. The flux through GCS was relatively high in the dog and low in the rabbit,
and only in the dog was it comparable with that through SPT/AGT. An in vivo experiment withl-[3-3H,14C]serine as the substrate indicated that in rabbit liver, gluconeogenesis froml-serine proceeds mainly via hydroxypyruvate. Because an important role in the conversion of glyoxylate to glycine has been
assigned to peroxisomal SPT/AGT from the studies on primary hyperoxaluria type 1, these results suggest that SPT/AGT in this
organelle plays dual roles in the metabolism of glyoxylate and serine.
Journal of Biological Chemistry 06/1999; 274(23):16028-16033. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: l-Serine metabolism in rat liver was investigated, focusing on the relative contributions of the three pathways, one initiated
by l-serine dehydratase (SDH), another by serine:pyruvate/alanine:glyoxylate aminotransferase (SPT/AGT), and the other involving
serine hydroxymethyltransferase and the mitochondrial glycine cleavage enzyme system (GCS). Because serine hydroxymethyltransferase
is responsible for the interconversion between serine and glycine, SDH, SPT/AGT, and GCS were considered to be the metabolic
exits of the serine-glycine pool. In vitro, flux through SDH was predominant in both 24-h starved and glucagon-treated rats. Flux through SPT/AGT was enhanced by glucagon
administration, but even after the induction, its contribution under quasi-physiological conditions (1 mm l-serine and 0.25 mm pyruvate) was about
of that through SDH. Flux through GCS accounted for only several percent of the amount ofl-serine metabolized. Relative contributions of SDH and SPT/AGT to gluconeogenesis from l-serine were evaluatedin vivo based on the principle that 3H at the 3 position of l-serine is mostly removed in the SDH pathway, whereas it is largely retained in the SPT/AGT pathway. The results showed that
SPT/AGT contributed only 10–20% even after the enhancement of its activity by glucagon. These results suggested that SDH is
the major metabolic exit of l-serine in rat liver.
Journal of Biological Chemistry 06/1999; 274(23):16020-16027. · 4.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Urinary trypsin inhibitor (UTI) inhibits efficiently tumor cell invasion and the formation of metastasis. The anti-metastatic effect is dependent on the COOH-terminal domain II of UTI [UTI-(78−136)-peptide]. To develop a molecule that binds with high affinity to the urokinase (uPA) receptor (uPAR) on tumor cell surfaces, a bifunctional hybrid molecule [uPA-(1−134)-UTI-(78−136)] consisting of the uPAR-binding NH2-terminal fragment [UTI-(78−136)-peptide] of uPA at the NH2-terminus of UTI-(78−136)-peptide was produced in Escherichia coli by genetic engineering. The purified hybrid protein inhibited trypsin and plasmin 2−3-fold less effectively than UTI-(78−136)-peptide and was found to bind to human tumor cells via uPAR, which was confirmed by cell binding and competition experiments. Using a modified Boyden chamber and an artificial basement membrane, Matrigel, it was found that the hybrid protein is very effective at inhibiting invasion by uPAR-expressing human tumor cells. Sensitivities of tumor cells towards the anti-invasive effect of uPA-(1−134)-UTI-(78−136) correlated with the density of uPAR on human tumor cells. Furthermore, in the spontaneous metastasis model, the hybrid protein inhibited the formation of lung and/or lymphatic metastasis by human ovarian carcinoma and choriocarcinoma cells. The hybrid protein was much more effective than uPA-(1−134)-peptide, UTI-(78−136)-peptide, or UTI. We conclude that this approach extends the possibility of applying recombinant protein for therapeutic use in inhibition of human tumor cell metastasis.
European Journal of Biochemistry. 04/1998; 253(3):817 - 826.
-
Hiroshi Kobayashi,
Yasuyuki Hirashima,
Guang Wei Sun, Michio Fujie,
Kiyoshi Shibata,
Satoshi Tamotsu,
Katsutoshi Miura,
Dan Sugino,
You Tanaka,
Satoshi Kondo,
Toshihiko Terao
[show abstract]
[hide abstract]
ABSTRACT: Urinary trypsin inhibitor (UTI) inhibits not only tumor cell invasion but also production of experimental and spontaneous metastasis. Cell-binding experiments indicated that human choriocarcinoma SMT-cc1 cells have specific binding sites for UTI on their cell surface. [Kobayashi et al., J. Biol. Chem. 269, 1994, 20 642–20 647]. UTI binding protein (UTIBP) was purified to homogeneity by a combination of UTI-coupled affinity beads, preparative polyacrylamide gel electrophoresis and reverse phase HPLC. This protein is very similar to a truncated form of human cartilage link protein (LP). LP was identified structurally by its apparent molecular mass with and without deglycosylation treatment: Immunologically by the reactivity with anti-UTIBP antibody, and functionally by its ability to bind the NH2-terminal domain of UTI. UTI and UTIBP are distributed uniformly in the cytoplasm and/or over the cell surface of tumor cells and fibroblasts. The level of staining for hyaluronic acid, UTIBP and UTI is much lower in sections digested with hyaluronidase. These results suggest that the cell membrane-derived UTI-associated binding protein is the LP of proteoglycan–hyaluronic acid aggregates, which interacts with hyaluronic acid. Cell-associated LP may play a role in modulating protease activity to the environment close to tumor and fibroblast cell surface.
Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology.
